Technical Field
The present application relates to a display control device and a display control system, both of which are provided for controlling displaying of images taken by a plurality of cameras each having a zooming function.
Related Art
In a studio or live place, for example, an attempt is often made to take and display a plurality of images simultaneously with a plurality of cameras each having functions of panning (i.e. rotating an orientation of lenses of a camera in a horizontal direction), tilting (i.e. rotating the orientation of lens of a camera in a vertical direction) and zooming (i.e. changing the magnification of a camera in a range from telephoto up to wide angle). Here, these cameras having such functions will be referred to as “PTZ cameras” after. Such a displaying operation with several cameras is frequently manipulated by only one operator.
In operation, when one operator operates a plurality of PTZ cameras to set a display magnification and also produce an image, exclusive operation elements (e.g. rotary operation elements) are manipulated by the operator. Then, due to a difference in the model and/or manufacture of the cameras, there is a case that respective variations in the magnification of respective cameras with respect to an operation amount of each operation clement differ from each other. Suppose, for example, a situation that respective magnifications of two cameras are established by operating their respective operation elements. Under the situation, if changing respective meter readers of both operation elements by the same operation amount of “x”, there may arise a possibility that the magnification of one camera changes with an amount of “y”, while the magnification of the other camera changes with an amount of “z” different from “y”.
In such a case, when setting the magnification of two cameras, it is difficult to produce an image where the magnification of the image has been changed according to an operator's will, because there is a difference in an operator's feeling against changing magnification between respective operation elements. Furthermore, if the number of cameras gets increased, an operator's feeling is further complicated to cause the operation to be difficult. Therefore, it is desired to unify the operability of respective operation elements in changing the displaying magnification of respective cameras, thereby improving the operability of respective operation elements.
Meanwhile, a camera itself has a problem of luminance unevenness (i.e. shading) caused by peripheral darkening of an optical system or inequality of sensitivity of an image pickup element and therefore, it is necessary to perform a shading correction to remove such shading. However, as the degrees of shading correction are different for the respective models of cameras, there arises a problem that obtained images are not made to be similar in quality. In Patent Literature 1 (U.S. Pat. No. 6,396,946 B1), there is described a technique of correcting an image taken by two cameras used for a stereo camera. However, Patent Literature 1 does not describe a technique of adjusting the quality of images of different types of cameras.